In Title Your Area 5: Amersham to Great Missenden

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1 LOCAL AREA In Title Your Area 5: Amersham to Great Missenden Find out here about: what is proposed between Amersham and Great Missenden; what this means for people living between Amersham and Great Missenden; and what would happen during construction. What is proposed between Amersham and Great Missenden? Once it emerges from tunnel west of Old Amersham, the proposed route would be in a deep narrow cutting, so that it would not be visible from most viewpoints. There would also be a 150 metre section immediately to the east of the A413 which would be roofed over to form a short green tunnel. The route would then pass into a single bore tunnel for ¾ mile beneath the Chiltern Line to the north-east of Little Missenden. After that the route would continue in a series of cuttings for 3½ miles beyond Great Missenden. To the west of South Heath the route would again be roofed over to create a green or cut and cover tunnel. Finally, at the end of this section of the route it would cross Grims Ditch, a scheduled monument. What this means for people living between Amersham & Great Missenden Tunnels (i) The proposed bored tunnel at Little Missenden This tunnel would start just to the west of Keepers Lane, and would then pass beneath the Chiltern Railways line between Amersham and Great Missenden Stations. It would next pass beneath Chalk Lane and would end just before Mantle s Wood. The tunnel would be slightly under a mile long. It would pass about 25m below ground level. It would be a single bore tunnel containing two tracks. The relatively short length of the tunnel means that no ventilation shafts would be required.

2 Any ground settlement caused by the tunnel construction would be imperceptible owing to the depth of the tunnel. All properties above the tunnel, however, would be independently surveyed before and after construction to ensure that in the very rare instance of any effects on property they would be rectified at no cost to the owner. Experience gained from HS1 in Kent and other high speed railways abroad has shown that potential effects from vibration and groundborne noise (audible vibration) in properties over tunnels can be avoided. HS2 Ltd is committed to ensuring that such impacts do not occur. The main construction site would probably be located between Keeper s Wood and Garden Plantation. Construction would take about four years. However, apart from building the portals (the tunnel entrance and exit), all other construction works would take place underground. We would work with local residents, businesses and Buckinghamshire County Council to devise construction methods that would minimise the impact during the construction phase. (ii) The proposed green tunnel at South Heath The green tunnel to the West of South Heath would be slightly over half a mile long and would run roughly between Chesham Road and Frith Hill. Green tunnels differ from bored tunnels. The former are built from the surface downwards, whereas bored tunnels are built from below the ground. A typical green tunnel We would expect the green tunnel to take between two and two and a half years to build. Construction would involve the digging of a cutting, building a tunnel structure within it and then covering it over with earth. We would aim to minimise the construction traffic movements and seek to use the earth dug from the trench to cover the tunnel and provide suitable landscaping for the local area. We do not expect that there would be any noticeable vibration effects for residents in the vicinity of the tunnel. Noise Between Amersham and Great Missenden the railway would pass in deep cutting and tunnel and as a result we currently predict that only a small number of households are likely to experience a perceptible increase in noise, and these are located in the areas marked in grey on the noise map in this factsheet. In most cases these would lie in close proximity to the proposed route. One area indicated in yellow on the noise map is predicted to experience a noise increase that would qualify for noise insulation as described in the current Railway Noise Insulation Regulations (NIRR). If the project is taken forward we would carry out more detailed noise assessments and consideration of noise mitigation to see whether these potential effects could be reduced or avoided.

3 Landscape, wildlife and habitats Much of the Chiltern Hills is designated as an Area of Outstanding Natural Beauty (AONB). Between Amersham and Great Missenden the proposed route would cross the AONB predominantly in tunnel and deep cutting, so that it would not be visible from most viewpoints. We would also use earth embankments, tree, hedgerow and shrub planting to screen views and blend the railway into the landscape. The proposed route would pass through several areas of ancient and semi-ancient woodland, including Garden Plantation, Keepers Wood, Mantle s Wood and Farthings Wood. To offset this, we would expect to carry out extensive planting of new trees. The new railway would provide scope for a green corridor of landscaped earthworks, habitats and planting alongside the route. Through the Chilterns the use of ancient woodland species could support a wider range of wooded habitats for local wildlife. Property and Land We expect that four homes would probably need to be demolished, situated to the east of Great Missenden. A further such property could be at risk of having some land taken, although once detailed design is carried out it may prove that this is not affected. Where the Government needs to compulsorily purchase and demolish individual properties we would not expect this to happen before 2015, and later than that in the majority of cases. Where dwellings need to be demolished owners would be fully compensated. Equally, where businesses would be affected they would be eligible for compensation. See factsheet Arrangements for Dealing with Property Blight for more details. Heritage The proposed route passes through the Grade II* Registered Park and Garden to the east of Shardeloes House. At this location the route would be lowered in the landscape using a combination of deep narrow cutting and a short green tunnel. These features would help to ensure that the landscape and wider setting of the House would be largely preserved. One Grade II listed structure to the south of South Heath would need to be moved or possibly demolished. Transport networks and access In order to build the proposed new line it may be necessary to rebuild existing road bridges in several places, for instance at Weeden Hill, Hyde Lane, Chesham Road, Frith Hill and Leather Lane. We will work together with local authorities in order to minimise any traffic disruption which might arise from this. Any effect on cycle routes and footpaths would be addressed as more detailed planning is done. Wherever possible routes would be reinstated or alternatives provided. So, for instance, the short green tunnel proposed where the rail line passes alongside the A413 would allow existing footpaths to cross over the new line. What would happen during construction? In consultation with local authorities and other key authorities, contractually binding conditions covering all aspects of construction would be put in place to regulate how works are conducted at each site. The effects of construction, for example dust, noise or traffic disruption, would be minimised through a combination of careful design, working with the local community and close management of the construction process. These conditions might be implemented, for

4 Noise Impact Key The map gives an indication of the properties that would experience noise once the proposed HS2 services are operating, based on our noise modelling, and assuming mitigation in place. Noticeable Noise Increase Areas which could have a perceptible change in average daytime railway noise levels where the predicted noise level is more than 50dBL Aeq,18hr and there has been a 3dB increase or more. Noise Insulation (NIRR) Areas which could have a requirement for noise insulation (based on regulations) where façade noise levels are more than 68dBL Aeq,18hr with a 1dB increase or more. High HS2 Noise Levels Within the areas which could qualify for noise insulation we have also identified locations which could be exposed to high average noise levels i.e. greater than or equal to 73dBL Aeq,18hr. This is the level taken from the Environmental Noise Regulations.

5 example, through Codes of Construction Practice, Environmental Management Plans or Traffic and Transport Management Plans. The construction site for the bored tunnel, which will run from the M25 until a point west of Old Amersham, would be located at the eastern end of the tunnel, not at Amersham. If you would like more detail on this topic Please visit our website where you will see the High Speed Rail: Investing in Britain s Future Consultation and all the documentation published alongside it, as well as detailed maps of the proposed route between London and the West Midlands and images and visualisations.

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